Propeller assembly for airships



y 19,1932. H. L. HAsE 1,867,809

PROPELLER ASSEMBLY FOR AIRSHIPS Filed Sept. 9 1930 2 Sheets-Sheet lINVENTO July 19, 1932. H. L, CHA E v 1,867,809

PROPE LLER ASSEMBLY FOR AIRSHIPS Filed Sept. 9, 1930 2 Sheets-Sheet 2 llW ENTOR WW1. 6M"

J26. 25%ATT0RNE Patented July 19, 1932 PATENT OFFICE HERBERT I. CHASE,01 DENVER, COLORADO PROIPELLER ASSEMBLY FOR AIRSHIPS 7 Application filedSeptember 9, 1930. Serial No. 480,702.

My invention relates to improvements in propeller assembly for airships.

' The primary object of the invention is to provide an improved form ofpropeller and an annular surrounding member or cowl therefor, wherebyall air acted upon by the ropeller is drawn thereby directly from theront, thuscontributing to the highest efficiency of the propeller.

Further, to provide an improved form of propeller for air ships havingwing members which. are so constructed that in operation they create avacuum at the front side of the propeller, the resultant air suctioncausing the air to compress at the rear of the propeller and asurrounding annular cowl which extends beyond both sides of thepropeller, its rear end being flared from a point substantially'coincident with the rear side of the propeller; whereby the expandingaction of the said compressed air against the said flared surface of thecowl, acts in conjunction with the thrust of the rear faces of the wingsagainst the said body of compressed air in propelling the ship.

Further to provide a substantially S- shaped propeller comprising a huband opposite wings, the tip portions of which are concentric w1th theaxis of the propeller, the cross sectional contours of said wings onlines concentric with the axis of the propeller, being in the form ofcompound curves, and their front faces being concaved; the perimeters ofsaid wings being tapered to form thin resilient blade-like portionswhich can move inward where the speed of the propeller is sufficient tocreate a vacuum in the concaved faces of the wings, or outward when thecentrifugal force is greater than the force created by the vacuum, thuspermitting an automatic adjustment of the blade-like portions of thewings under varying speeds of the propeller.- These objects areaccomplished by the mechanism illustrated in the accompanying. drawingsin which:

Fig. 1 is a front view of the improved propeller.

Fig. 2 is a rear view of the same. Fig. 3 is a sectional view thereof,on the line 33 of Fig. 1. v

Fig. 4i is an end view of the propeller.

Fig. 5 is a sectional view on the line 5-5 Of Fig. 1.

Fig. 6 is a side view of the forward portion of an airship equipped withthe improved propeller, which is surroundedbya cowl which forms acooperative part of my invention, the cowl being in section.

Fig. 7 is a side view of the cowl and Fig. 8 is a front view of the cowland propeller.

In normal flight an airship is pulled along by the thrust of thepropeller and in the 5 present case the propeller thrust is augmented bythe expanding action of the air against the flared wall of the rear endof the cowl, as the air is drawn through the cowl by the suction actionof the propeller as will hereinafter be fully described.

Referring to the accompanying drawings:

The letter A designates the forward portion of an airship, B theimproved propeller, and C the cowl which surrounds the propeller.

The improved propeller is substantially in the form of an elongated Sand comprises a hub 1 and oppositely extending outwardly curved wings 2,the tip portions of which .are concentric with the axis of thepropeller.

Each wing, from its forward or advancing edge to its rear edge is of thecross sectional outline shown in Fig. 5 or is in the form of a compoundcurve, and the marginal edge or perimeter of each wing is curved orrolled on its rear side, from the point of its connection with the hubto about the point 4, from which point to. the tip, it merges into aflat face as shown at 5. The front faces. of 00 v thin resilientblade-like member 8 or if desired, this blade-like portion may be a thinv resilient strip which is secured to the perimeter of the wing.

The blade ortions in either case are thin enough to e resilient,

' for a purpose to be hereinafter explained,

and the tips of the blades extend slightly beyond the rear edges of thewings, as shown at 9. I

The propeller may be secured to its driving shaft in any suitablemanner, and it is surrounded by a cowl C which is arranged andconstructed in the following manner:

, The cowl is in the form of a band or ring, the outer face of whichtapers toward its rear rim at any angle which may prove most effective,while its inner face is preferably bell-shaped for about two-thirds ofits length, as shown at 10, from which point it flares to its rear rim,as shown at 11. The front rim of the cowl extends slightly beyond thefront face of the propeller and the rear face of the propellerextends-slightly beyond the point where bell-shaped surface of the cowlmerges into the flared surface, as clearly shown in Fig. 6 and there isonly a slight space between the tips of the propeller and the wall ofthe cowl at this point. The cowl may be secured to the airship in anysuitable manner, as by strap irons-12, which are secured to the cowl andto the forward end portion of the ship.

By surrounding the propeller with the cow air approach to the propellercan only be directly from the front, the air being cut off in all otherdirections. The rapid rotation of the propeller creates a vacuumwithinthe concaved faces ofthe wings, and the resultant suction forcedraws the air into the propeller 1n a stream, which-is confined andlimlted by the cowl, and as this'air is forcibly ejected rearwardly, itforms a compressed body back of the propeller andas this compressed bodyof air expands against the flared face of the cowl, it naturally exertsa for'-. ward thrust against the cowl, which is in addition to thethrust of the rear faces of the propeller wings against the said body ofcompressed air, and thus the ship is carried forward under the directsuction force from the front, and the thrust of'the pro eller, plus theexpanding action of a body 0 compreslsed air against the flared face ofthe cow a The construction of the improved propeller is such that rapidrotation creates a vacuum in the concaved faces of the wings, causing apowerful air suctionthroughthe propeller and the wings move so rapidlyaway from peller.

the in-rushing air, that they offer no impediment to the same. Bysurrounding the pro-. peller with the improved cowl, all of the radialforce exerted by the suction of the propeller is converted into directsuction force from the front. The resiliency of the tip portions of'thewings permits of their lateral movement under varying speeds, of thepropeller, so that they adjust themselves automatically according to thespeedof the propeller and it has been found after repeated tests thatthe propeller has greater lifting power when the tip portions arethinned to a resilient condition than when they are rigid and it'hasalso been found that the improved propeller develops far more power persquare foot of surface within the circumference of the propeller at anygiven rate of speed than is developed by the usual type of propeller atY Having described my invention, what I I claim as new and desire tosecure by Letters Patent, is:

1. A propeller of the character described which is substantiallyS-shaped andv comprises a hub and oppositely extending wings, said Wingsbeing in the form of compound curves in cross section, and beingconcaved on their front faces, the concavities disappearing near theiradvancing edges; the perime- I ters of said wings being rolled on theirrear sides and tapered to thin resilient blades.

2. A propeller of the character-described which is substantiallyS-shaped and comprises a hub and oppositely extending wings, each ofsaid wings being in the form of a compound curve in cross sectiontakenon a l1ne concentric with the axis of the propeller,

and being concavedon its front face, the concave disappearing near itsadvancing edge;.

the perimeter of the wing being rolled on its rear side and tapered to athin resilient blade, the tip of which extends beyond the rear edge ofthe wing.

3. A propeller of the character described, which is substantiallyS-shaped and comprises a hub and oppositely extending wings each ofwhich is in the form of a compound curve in cross section taken on aline concentric with the axis of the propeller, and is concaved on itsfront face from its perimeter to the hub, the bottomof said concavitybeing substantially semi-circular in radial section, the perimeter ofthe wing being curved transversely on its rear side to correspond withthe curvature on its front side, said perimeter being concaved on theirfront faces,- and being in the form of compound curves on linesconcentric with the a'xis of the propeller, said concavitiesdisappearing near the advancin edges of the Wings, the advancing edges 0the propeller wings being curved tangentially to the axis of thepropeller beginning at the hub and gradually merging into concentriccurves near their tips, the concentric portions of the Wings beingtapered to thin resilient blades.

In testimony whereof, I aflix my signature.

HERBERT L.

